The goal of this project is to isolate and characterize genes that are important to the development and function of the Drosophila visual system and to use them to identify human homologs. Two new directions have emerged. One is to use mutant analysis to understand the roles of glia in the visual system and the other is to explore the nature of the interphotoreceptor space in Drosophila. The applicant will continue to use genetic screens and monoclonal antibodies to initiate these studies.